The Australian SKA Pathfinder (ASKAP) is being used to undertake a campaign to rapidly survey the sky in three frequency bands across its operational spectral range. The first pass of the Rapid ASKAP Continuum Survey (RACS) at 887.5 MHz in the low band has already been completed, with images, visibility datasets, and catalogues made available to the wider astronomical community through the CSIRO ASKAP Science Data Archive (CASDA). This work presents details of the second observing pass in the mid band at 1367.5 MHz, RACS-mid, and associated data release comprising images and visibility datasets covering the whole sky south of $\delta_{\text{J2000}}=+49^\circ$. This data release incorporates selective peeling to reduce artefacts around bright sources, as well as accurately modelled primary beam responses. The Stokes I images reach a median noise of 198 $\mu$Jy PSF$^{-1}$ with a declination-dependent angular resolution of 8.1–47.5 arcsec that fills a niche in the existing ecosystem of large-area astronomical surveys. We also supply Stokes V images after application of a widefield leakage correction, with a median noise of 165 $\mu$Jy PSF$^{-1}$. We find the residual leakage of Stokes I into V to be $\lesssim 0.9$–$2.4$% over the survey. This initial RACS-mid data release will be complemented by a future release comprising catalogues of the survey region. As with other RACS data releases, data products from this release will be made available through CASDA.

Research on hardened daub fragments provides highly relevant data on the building activities of past societies. Unfortunately, in many cases these elements are not considered relevant research objects, resulting in a very important loss of information for archaeology. There is still a long way to go in the studies of earth building remains, the vast majority of which have focused on assemblages coming from specific sites. Likewise, a good number of these studies carried out from a macroscopic approach either have not published the methodology used or barely offer some considerations about it. This article approaches the methodological procedures for their analysis through direct observation, while hoping to contribute to making these remains more visible and to facilitate and promote their study. This methodological proposal can be applicable to materials of different composition and from very different contexts, chronologies, and origins.

This paper draws on archival research to trace the techniques used by scientists and government officials involved with palm oil at the turn of the twentieth century. For them, mundane practices of “carefulness” were paramount as they worked on collecting, identifying, marketing, and improving the oil palm. But they also applied this so-called care to people: care of the oil palm was thought to presuppose care of the “native,” providing a correction for what were seen as “careless” local manners of cultivation. Colonial techniques of care thus sought to encompass both plants and peoples within contemporary liberal rhetorics of efficiency and moral improvement. This embodies how scientific and political care can interlink through their undersides of control, exploitation, and domination, which remain obscured by narratives of care themselves. Examining these links between commodity histories and scientific techniques is therefore essential for understanding environmental and social concerns regarding oil palm plantations today. An awareness of the afterlives of colonial discourses might encourage a more critical “care” in response to these issues today, challenging taken-for-granted notions of the benefits of corporate care.

Dans cet article, nous étudions l'axiologie des techniques des discours écologistes de la décroissance à l'aune de celle du philosophe français Gilbert Simondon. Cette articulation fertile permet de montrer, premièrement, que les discours de la décroissance n’évaluent les techniques qu’à partir de leurs usages ; deuxièmement, elle explique pourquoi une telle axiologie, praxéologique plutôt que technologique, est incapable d'influer sur le progrès technique. À partir de Simondon, nous montrons notamment que la pensée de la décroissance ignore la distinction entre information et énergie au sein des réalités techniques, distinction pourtant nécessaire si l'on souhaite relier l’étude des techniques et l’écologie de façon adéquate et constructive.

The calibration hardware system of the Large Synoptic Survey Telescope (LSST) is designed to measure two quantities: a telescope’s instrumental response and atmospheric transmission, both as a function of wavelength. First of all, a “collimated beam projector” is designed to measure the instrumental response function by projecting monochromatic light through a mask and a collimating optic onto the telescope. During the measurement, the light level is monitored with a NIST-traceable photodiode. This method does not suffer from stray light effects or the reflections (known as ghosting) present when using a flat-field screen illumination, which has a systematic source of uncertainty from uncontrolled reflections. It allows for an independent measurement of the throughput of the telescope’s optical train as well as each filter’s transmission as a function of position on the primary mirror. Second, CALSPEC stars can be used as calibrated light sources to illuminate the atmosphere and measure its transmission. To measure the atmosphere’s transfer function, we use the telescope’s imager with a Ronchi grating in place of a filter to configure it as a low resolution slitless spectrograph. In this paper, we describe this calibration strategy, focusing on results from a prototype system at the Cerro Tololo Inter-American Observatory (CTIO) 0.9 meter telescope. We compare the instrumental throughput measurements to nominal values measured using a laboratory spectrophotometer, and we describe measurements of the atmosphere made via CALSPEC standard stars during the same run.

The current study aimed to test whether organic matter intake by free-ranging ruminants could be estimated from the amount of nitrogen (N) excreted in faeces and to compare this approach to conventional techniques. An equation describing the relationship between excreted N and nutrient intake was developed in indoor digestibility trials conducted with male sheep (n = 36) and cattle (n = 24) housed in metabolism cages and solely fed hay harvested from a local rangeland. Faecal N excretion was linearly related to organic matter (OM) intake without a significant animal species effect. To evaluate the linear equation, data from free-ranging trials conducted with sheep and cattle were used. The faecal N approach was compared with either in situ digestibility plus external marker (n = 123) or n-alkanes (n = 272) to estimate OM intake and digestible OM intake. Estimates obtained through the faecal N approach did not closely fit those obtained with either conventional technique for any variable. Averaging all individual values, the supply of metabolizable energy (ME) estimated through faecal N was similar to the required level, whereas both the in situ and n-alkanes techniques overestimated ME supply. In conclusion, OM intake by free-ranging sheep and cattle can be estimated based on the amount of N excreted in faeces with some advantages over conventional techniques: knowledge about herbage attributes is not required and it accounts for individual variability on selectivity and digestion processes.

We developed a flare prediction model based on the supervised machine learning of solar observation data for 2010-2015. We used vector magnetograms, lower chromospheric brightening, and soft-X-ray data taken by Solar Dynamics Observatory and Geostationary Operational Environmental Satellite. We detected active regions and extracted 60 solar features such as magnetic neutral lines, current helicity, chromospheric brightening, and flare history. We fully shuffled the database and randomly divided it into two for training and testing. To predict the maximum size of flares occurring in the following 24 hours, we used three machine-learning algorithms independently: the support vector machine, the k nearest neighbors (kNN), and the extremely randomized trees. We achieved a skill score (TSS) of greater than 0.9 for kNN. Furthermore, we compared the prediction results in a more operational setting by shuffling and dividing the database with a week unit. It was found that the prediction score depends on the way the database is prepared.

Weed scientists are trained broadly in agronomy, botany, chemistry, soils, and other agricultural disciplines. The study of weeds, rather than the techniques used or the questions asked, unifies weed scientists around a common focus. It is often difficult for weed scientists to identify closely with any one scientific discipline, since the techniques and questions of many disciplines are needed to address problems posed by weeds. One discipline with relevance and potential for addressing weed science problems is physiological ecology. The study of the functioning or adaptation of plants in relation to environmental influences has its roots in both classical ecology and experimental physiology. Application of this discipline to weed science may take an environmental approach (e.g., studying limiting factors in the environment), a physiological approach (e.g., studying the responses of critical plant processes to environmental stress), or a more autecological approach (e.g., studying the physiological basis for the adaptation of a particular weed to a particular habitat). Many methodologies and technologies are available for both field and laboratory investigations. For example, photosynthesis, a major determinant of plant growth, can be investigated in the field at the leaf, plant, or canopy level using plant growth analysis or a portable infrared gas analyzer (IRGA) and appropriate assimilation chambers. Investigations of photosynthesis in the laboratory can focus on the plant, leaf, chloroplast, or thylakoid level using an IRGA or the techniques of polarography (measurement of evolved oxygen) or fluorometry. Application of such approaches to weed science should improve our understanding of the basis for particular weed problems and thus broaden our options for management.

Different Saskatchewan soils were studied to determine their populations of 2,4-D [(2,4-dichlorophenoxy) acetic acid] degraders and gross aerobic bacteria. Soil from Indian Head field plots receiving relatively high field rates (1.12 or 1.68 kg/ha) of 2,4-D amine or ester applied annually over the previous 32 yr contained the highest population of degraders, ranging from 103 to 104 degraders/g soil. Control plots recorded lower populations of degraders (2.5 ± 0.5 × 103 degraders/g soil). Five soils from around the province were also studied, and a relationship was found between the rate of breakdown of 14C-2,4-D in the soil and the number of degraders. Another soil from a different site at Indian Head, but of a similar type to that in the field plots, displayed a much slower rate of 2,4-D degradation and also a much lower degrader population (7 ± 2 degraders/g soil) when compared to the other four soils (4 × 102 to 9 × 102 degraders/g soil). The ratio of degraders to the total bacterial flora varied in all studies between 1:6.5 × 102 and 1:3 × 105. When 1030 soil isolates were screened for their ability to degrade 2,4-D using an agar-block extraction technique, none possessed this feature. This would support the hypothesis that the ratio of 2,4-D degraders to the total microbial flora was indeed large (at least 1:103).

Radio astronomy software has not quite kept up with recent developments for the display of, and interaction with, data. At the Australia Telescope National Facility we are trying to catch up by investigating how useful visualisation techniques and approaches like visual computing are for the reduction of radio data. I will discuss a few techniques that we have applied to radio data and comment briefly on their merits.

This paper is based on a report given at the ASA Conference in July 1994, but takes account of subsequent developments up to the end of the year. The present state of the Two-degree Field (2dF) project for the AAT is reported. Good progress is being made on all fronts but some slippage has occurred, so that the instrument is now expected to begin astronomical observations only during the second half of 1995. An outline of other current and future instrumentation plans at the AAO is given.

There is a wide spectrum of techniques available to evaluate the functional aspects of the immune system in both humans and animals, including avian species. Some of the immunological techniques are qualitative and others are quantitative. In this paper, these techniques will be reviewed starting with a description of the nature of the antibody-antigen interaction, followed by the immune techniques that are used to detect immune complexes (i.e. antigen-antibody responses) whether free or associated with cells, then the numerous immune markers or parameters that are used to measure the avian immune responses.

A discharge-emission spectrometer and a cavity ringdown spectrometer have been developed to aid in the solution to the diffuse interstellar band (DIB) problem. A hollow cathode was used to generate molecular ions in a discharge because it has been suggested that molecular ions are probable DIB candidates. The discharge was produced by a pulsed voltage of 1300–1500 V. A wide wavelength range of optical emission from the discharge was examined by a HORIBA Jobin Yvon iHR320 monochromator. The dispersed discharge emission was detected by a photomultiplier and was recorded via a lock-in amplifier. The 2B3u–X2B2g electronic transition of the butatriene cation H2CCCCH2+ was observed in the discharge emission of 2-butyne H3CCCCH3. The frequency of the electronic transition was measured to be 20381 cm−1, and a comparison study was made with known DIB spectra.

The resolution of the discharge-emission spectrometer is insufficient to make precise comparisons between laboratory frequencies and astronomically observed DIB spectra. We therefore developed the cavity ringdown spectrometer using the same hollow cathode. The high sensitivity of this spectrometer was confirmed by the observation of the forbidden band of O2.